let getTime = (seconds) => {
    return new Promise(res => {
        setTimeout(() => {
            res(seconds)
        }, seconds)
    })
}

async function test(){
   let arr = [getTime(2000),getTime(500),getTime(1000)]
   for await (let x of arr){
       console.log(x); 
   }
}

test() //以此执行 2000  500 1000